UPR 5301

Redox-responsive maltoheptaose-b-polystyrene nanoparticles containing zinc phthalocyanine: Formulation, photophysical properties, release kinetic and toxicity

In this article by Sami Halila and Redouane Borsali, in collaboration with the Federal University of Santa Maria (Brazil) and the Ningbo Institute of Materials Technology and Engineering, (China), we show that self-assembled biocompatible glyconanoparticles encapsulating zinc phthalocyanine photosensitive allow by the action of two different stimuli to release the active agent for photodynamic therapy of cancer.

Abstract :

« Sugar-based nanoparticles with redox responsive properties are an emerging class of nanovehicles designed to boost photodynamic therapy (PDT) in the treatment of neoplastic and non-neoplastic diseases. In this paper, it was synthesized a maltoheptaose-b-polystyrene [MH1.2kb-PS5k)] block copolymer using metal-free click reaction, containing a redox-cleavable linker. The glyconanoparticles, loaded with photosensitizer zinc phthalocyanine (ZnPc) were produced by block copolymer self-assembly in an appropriate solvent mixture. The hydrodynamic radius of the nanoparticles (MH1.2kb-PS5k@ZnPc) was dependent on copolymer concentration and method of nanoprecipitation (standard or reverse). The polymeric micelles displayed a spherical morphology, suitable values of efficiency encapsulation and kinetics profile showed a burst release at first stage, followed by a sustained release controlled by diffusion. The nanocarriers were able to produce cytotoxic singlet oxygen (1O2) and displayed appropriate values of singlet oxygen quantum yields (). The MH1.2kb-PS5k@ZnPc nanoparticles were non-toxic towards Caernohabditis elegans and do not induced delay on larval development on dark conditions. The redox-responsive cleavage of block copolymer by N-bromosuccinimide (NBS) and MH1.2kb-PS5k@ZnPc nanoparticles by NBS or reduced glutathion (GSH) was evidenced through by several techniques. These outcomes highlight that glyconanoparticles are stimuli-responsive and can contribute to the development of third-generation photosensitizers for use in PDT. »

The publication is available on the Editor’s website :

https://www.sciencedirect.com/science/article/abs/pii/S1773224723006901